Weird idle characteristics while braking (?) .... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

nathanong87 · 11-18-2009, 09:16 PM

essentially when i'm in 3rd/4th gear and around 3k rpms, i take the car into neutral and pull to a stop while braking. When i do the above, my rpms drop down to near stalling.

when i simply coast (not applying the brake), my idles go from 3k to 700-800 (which i think is "normal")

i am thinking it's yet a vacuum leak somewhere, but i just wanted to see what some of you gurus thought about this. I'm no expert by any means.

thanks in advanced!

AznXstazy · 11-18-2009, 09:26 PM

sounds like the ivac. try cleaning it.

M11's · 11-18-2009, 09:35 PM

for sure check for vac leaks. iacv, clean maf, clean in throttle body. Bed its vacuum tho.

nathanong87 · 11-19-2009, 04:58 AM

thanks, i'll check the IACV for sure. i mean it's more annoying that not

Mangudai · 11-20-2009, 04:44 PM

Do you have an auto ecu?

Ceepo · 11-20-2009, 05:14 PM

are you ka or sr?

In my sr20det(redtop) when i press the brake the car wants to die, imo i think its the current draw to the lights putting a load on the alternator and causing the motor to go sluggish for a second while the ecu kicks up the rpms, all my freinds cars do it... Sounds like a pretty good theory to me lol...

nathanong87 · 11-24-2009, 12:28 PM

Quote:

Originally Posted by Mangudai

Do you have an auto ecu?

negative

Quote:

Originally Posted by Ceepo

are you ka or sr?

In my sr20det(redtop) when i press the brake the car wants to die, imo i think its the current draw to the lights putting a load on the alternator and causing the motor to go sluggish for a second while the ecu kicks up the rpms, all my freinds cars do it... Sounds like a pretty good theory to me lol...

SR, i also contemplated this theory as music is being played really loud, headlights are often on, and braking will bring up the brake lights. HRMMMMmmmm

HOWEVER, i believe that the car is "stalling" whilest stopping quickly, which will disprove the brake lights having to play a factor. I can brake slowly while in neutral and come to a stop withtout the engine's RPMs dropping suddently to "0"

nothix · 11-24-2009, 02:34 PM

Quote:

Originally Posted by Ceepo

are you ka or sr?

In my sr20det(redtop) when i press the brake the car wants to die, imo i think its the current draw to the lights putting a load on the alternator and causing the motor to go sluggish for a second while the ecu kicks up the rpms, all my freinds cars do it... Sounds like a pretty good theory to me lol...

had this same exact issue. Ran a ground cable straight from the battery to the brake light ground (battery is in the trunk) and problem is completely gone. Give this a try.

as for dieing without pressing the brakes. Check for vacuum leaks, clean TB and IACV, and recirculate your BOV.

nathanong87 · 02-07-2010, 02:54 PM

just re-visiting this thread, but i found out it was a small small small boost leak near my FMIC couplers

11-18-2009, 09:16 PM	#1
nathanong87 Post Whore! Join Date: Jul 2006 Location: maryland Age: 33 Posts: 5,182 Trader Rating: (6) Feedback Score: 6 reviews	Weird idle characteristics while braking (?) .... essentially when i'm in 3rd/4th gear and around 3k rpms, i take the car into neutral and pull to a stop while braking. When i do the above, my rpms drop down to near stalling. when i simply coast (not applying the brake), my idles go from 3k to 700-800 (which i think is "normal") i am thinking it's yet a vacuum leak somewhere, but i just wanted to see what some of you gurus thought about this. I'm no expert by any means. thanks in advanced! Last edited by nathanong87; 11-19-2009 at 04:50 AM..

11-20-2009, 04:44 PM	#5
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	Do you have an auto ecu? __________________ Almost there.

11-20-2009, 05:14 PM	#6
Ceepo Nissanaholic! Join Date: Jan 2008 Location: Cedar City, Utah Posts: 2,007 Trader Rating: (9) Rides Gallery: Ceepo Feedback Score: 9 reviews	are you ka or sr? In my sr20det(redtop) when i press the brake the car wants to die, imo i think its the current draw to the lights putting a load on the alternator and causing the motor to go sluggish for a second while the ecu kicks up the rpms, all my freinds cars do it... Sounds like a pretty good theory to me lol... __________________ TW: http://zilvia.net/f/cars-sale/390459...d9s-coils.html

02-07-2010, 02:54 PM	#9
nathanong87 Post Whore! Join Date: Jul 2006 Location: maryland Age: 33 Posts: 5,182 Trader Rating: (6) Feedback Score: 6 reviews	just re-visiting this thread, but i found out it was a small small small boost leak near my FMIC couplers __________________ IG @nathanong87 --- Night ★ Life natelife.tumblr.com

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11-18-2009, 09:26 PM	#2
AznXstazy Zilvia Member Join Date: Apr 2006 Location: Bleh Posts: 154 Trader Rating: (2) Feedback Score: 2 reviews	sounds like the ivac. try cleaning it.

11-18-2009, 09:35 PM	#3
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	for sure check for vac leaks. iacv, clean maf, clean in throttle body. Bed its vacuum tho.

11-19-2009, 04:58 AM	#4
nathanong87 Post Whore! Join Date: Jul 2006 Location: maryland Age: 33 Posts: 5,182 Trader Rating: (6) Feedback Score: 6 reviews	thanks, i'll check the IACV for sure. i mean it's more annoying that not